Air or gas compressor



(No Model.)

S. S. MILES. AIR 0R GAS GOMPRESSOR N0. 591,137. Patented Oct. 5,1897..

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PATENT EricE.

STEPHEN s. MILES, or cINcINNAT oHIo.

AIR OR GAS COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 591,137, dated October 5, 1897. I

Application filed July 9,1896. Serial No. 598,589. (No model.) I

T and whom it may concern: 7

are first to rovide a com ressor the 0 era- P P tive parts of which can be kept cool by the return gas and automatically lubricated by the oil circulated with said gas, and, second, in certain details of arrangement and construction, all of which will be fully set forth in the description of the accompanying drawings, in which- I Figure 1 is a central horizontal section through my compressor. Fig. 2 is a central vertical section through the same. Fig. 3 is a section on line 00, Fig. 2. Fig. 4 is a detail top plan view of one of the crank-shaft journals. Fig. 5 is an inside face view of the same, partly in section.

A represents the casing, which also serves as the main frame of the compressor; B B,

the cylinders; O C, the plungers, and DD the cylinder-heads.

The casing A is of cylindrical form and is preferably mounted upon abed-plate a. The cylinders, which are of plain tubular form, without jackets or other openings cast in their walls, are let into the ends of the casing and are secured thereto by means. of stud-bolts passing through the flanges b b at the outer ends of the cylinders, said stud bolts also serving to clamp the cylinder-heads in place.

The inner ends of the cylinders are preferably held in position by means of annular ribs E, cast with the casing A.

F represents the crank-shaft, F the driving-pulley, and G G pitmen connecting the plungers with the crank-shaft.

c 0 represent the inlet-valves, located in The crank-shaft is mountedin j ournal-bearings formed in the removable head-plates J J'.

K K represent stuffing-boxes to prevent the passage of gas or air in either direction through the journals.

L represents oil-cups, preferably cast with and upon the inner faces of the head-plates J J, the cups being provided with passages admitting oil into the journal-boxes, as shown in Figs. 4 and 5.

M represents a manhole by means of which the operative parts may be reached.

The mode of operation is as follows: A sufficient quantity of oil is supplied in the casing A, sothat the crankshaft and pitmen will dip in it at their lowest position. The pump is then started. The cool return gas enters through branch pipe II and passes around the cylinders and through the passage e in the rib E into the central chamber of the casing, from whence it passes through the inlet-valves c 0 into the cylinder. From there it is forced by the plungers through exit-valves cl (1, through passages I I, and pipes to the condenser and is ultimately returned through pipe H. The oil in main frame is thrown by the crankshaft and pitmen into the cylinders and onto the head-plates J J, keeping the cylinders lubricated and supplying oil to the cups L, the oil and all parts of the compressor except the cylinder-heads being kept cool bythe circulation of the return gas. A small quantity of oil works through the cylinders into the pipesand is finally returned with the gas through pipeH. The rib E may be omitted, but is preferably employed, as it serves to support the inner ends of the cylinders and also as a partition to direct the return gas and cause it to circulate entirely around the cylinders.

Considerable difficulty .is experienced in casting cylinders without air-holes and otherwise suitable forgas-compression cylinders. These difficulties I reduce to a minimum by the construction herein shown. The cylinders and wearing parts are so arranged as to be readily produced and replaced without replacing the casing and inoperative parts.

Having described my invention, what I claim is 1. In an air or gas compressor, the combination of a casing, a cylinder wholly inclosed in said casing and having an open end or mouth projecting into said casing and its other end provided with a flange that closes that end of the casing, a cylinder-head that is bolted to the flanged end of the cylinder and also to the casing, there being an annular jacketspace between said'cylinder and casing and wholly surrounding the said cylinder, an annular rib or partition between the casing and the inner end of the cylinder, said partition being provided with a passage for communication between the j acket-space and the main interior portion of the casin g, a pipe for admission of return gas to the annular jacket-space and thence around the cylinder and to the casing through the passage in the annular partition, a plunger provided with an inletvalve to the cylinder, an exit-valve in the head of the cylinder, and a pipe from said exit-Valve to a condenser, substantially as described.

2. In an air or gas compressor, the combination of a casing having a cranked shaft centrally therein, cylinders projecting into opposite ends of said casing and wholly inclosed therein with intermediate annular jacketspaces, annular ribs or partitions between the casing and,,the inner ends of said cylinders and each provided with a passage for communication between the jacket spaces and the central portion of the casing, inlets for admission of return gas into the annular jacket-spaces to circulate around the cylinders and into the central portion of the casing, plunger-s carried by the central cranked shaft and provided with inlet-valves to the cylinders, exit-valves in the cylinder-heads, and pipes from said exit-Valves to a condenser, substantially as described.

In testimony whereof I have hereunto set my hand.

STEPHEN S. MILES. \Vitnesses:

WM. E. Bnoo s, O. W. MILEs. 

